Effects of Rosemary extracts on oxidative stability of chikkis fortified with microalgae biomass
The present study evaluates the oxidative stability in chikkis enriched with omega 3 fatty acids using natural antioxidant from Rosmarinus officinalis. The best condition for the extraction of phenolic compounds from Rosmarinus officinalis L. (rosemary) was established, and the antioxidant activity was demonstrated based on inhibition of DPPH free radical formation. Nannochloropsis oculata and Isochrysis galbana are rich sources of Eicosapentanoic acid (EPA) and Docosahexaenoic acid (DHA). Biomass of these microalgae were incorporated in chikkis as omega 3 fatty acid source. Effects of addition of natural and synthetic antioxidants (BHA) on oxidative stability of chikkis were analyzed for storage period of 2 months. Evaluation of peroxide value (PV) and fatty acid profile showed that the process of oxidation slowed down. Natural antioxidant was found to be more effective when compared to synthetic antioxidant (BHA). Omega-3 PUFA levels (EPA+DHA) of 75 and 240 mg/100 g chikkis were observed if enriched with 1 and 3 % Nannochloropsis oculata biomass respectively. Similarly, Omega-3 PUFA levels (EPA+DHA) of 102 and 320 mg/100 g chikkis were observed if enriched with 1 and 3 % Isochrysis galbana biomass respectively. The effects of microalgae and antioxidant incorporation on the chikkis showed that color values remained stable during storage period of 2 months with no significant change (P < 0.05) in texture. Sensory evaluation revealed that up to 3 % microalgal biomass incorporation was positively classified and accepted.